Characterization and modeling of interface delamination in 3D stacked package with combination of experimental and CZM analysis

The focus of this paper is to investigate the interface delamination between the chip and substrate in 3D stacked packaging, where the interface is bonded together by a Die Adhesive Film (DAF) layer. Firstly, we conducted an analysis of the interface based on fracture mechanics theory. Considering that Mode I and Mode II are typically the primary failure modes in engineering applications, this paper primarily discusses these two fracture modes. We designed single cantilever beam (SCB) and four-point bending (4PB) tests based on the two failure modes and calculated the critical energy release rates, GIC and GIIC, through computation of the test results. Additionally, utilizing the fracture analysis module in Ansys finite element analysis software, we obtained the parameters required to establish the cohesive zone model (CZM) through simulation, which characterizes the initiation and propagation of cracks. We also discussed the influence of the critical shear strength on the critical load in the simulation analysis. Finally, we found that the obtained CZM not only characterizes the occurrence and propagation of cracks at the interface between the chip and substrate in 3D stacked packaging but can also be applied to study similar interfaces in other types of packaging. Overall, the research findings of this paper have significant reference value for analyzing interface delamination between chips and substrates.